It all depends on context. "I'm going to go hang out with the guys." yes, exclusive. "Hey guys, I'm going to work." not exclusive. Try focusing on the meaning being conveyed and not the glyphs representing it.
I understand how ingrained the “guys” habit might be for
some of you. It was for me. After several months of
concerted, conscious effort, I still slip and say it on oc-
casion.
So even the author herself used the word with completely gender neutral intent, but then she insists that others can't. It's like she's looking for reasons to be offended.Either way, that's no excuse to stop thinking about things.